<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>验证邮箱有效性</title>
    <script type="text/javascript" src="js/a.js"></script>
</head>
<body>
<button onclick="isEmail(prompt('请输入正确的邮箱地址','baiquan@qq.com'))">点击我</button>


</body>
</html>